This invention relates to roofing safety devices in general, and, in particular, to self-locking anchorages.
The perils of working on rooftops are well documented. The crumbling of a roofing tile beneath the feet of a worker, or a simple stumble can result in a crippling injury or even death. For this reason, safety regulations typically require that roofing workers utilize one of various prescribed safety devices.
In general, however, roofers work without the benefit of any form of safety device. Although there are a number of reasons for this, two of the primary reasons are the cost and inconvenience of utilizing the safety devices heretofore available. Safety nets, for example, are difficult to set up and must be moved repeatedly as the workers cover the various sections of the roof. Safety rails suffer from similar shortcomings.
In an effort to provide a relatively inexpensive safety device which can be quickly and easily installed, a safety device has been developed which incorporates an upright support and a spring-loaded spool and cable safety block secured to the top thereof. The fixed end of the cable is secured to a spring-loaded spool within the block's outer housing. The free end of the cable is attached to a ring which is secured to a belt or harness, adapted to be worn by the worker. As the worker walks away from the upright support, tension on the cable will exceed the force of the spring, thereby unwinding the spool. When the worker approaches the upright support, tension on the cable will be less than the force exerted by the spring, and the spring will cause the spool to rotate, winding the cable inwardly until the tension on the cable is equal to the force of the spring. If the rate at which the cable unwinds from the spool exceeds a certain rate, corresponding to the early stages of a fall, a brake mechanism will engage, thereby preventing additional cable from unspooling and halting the movement of the worker away from the support.
The upright support of this safety device is formed by a central shaft and a pair of bracing arms. The lower end of the central shaft and each of the bracing arms is rotatably secured to a flat rectangular foot, rotatable about a horizontal axis, perpendicular to the axis of the support. The feet are adapted to be affixed to the framework of the roof, so as to secure the safety device thereto.
Unfortunately, however, use of this safety device has a number of significant drawbacks. First, the feet of the device cannot be secured to many of the wide variety of roof configurations on which the average roofer must work. Often, for example, where the roof is stepped, the feet of the device cannot be aligned with the surrounding surfaces. This is significant, because roofers, like most people, are creatures of habit, and if they become accustomed to using a safety device at all times, they will tend to always use it. If, on the other hand, they find the safety device to be difficult or impossible to install on a significant percentage of roofs, they are apt to neglect using the device even on roofs where it could be easily installed.
Secondly, even on those roofs for which the alignment of the feet with the surface of the roof is possible, the feet of the safety device can often only be aligned with the plywood sheets covering the roof, rather than the supporting beams, thereby significantly limiting the capacity of the device to bear a substantial impact. This too is a shortcoming not likely to be overlooked by the roofers. Any inconvenience for the purpose of utilizing a safety device is only likely to be endured if the workers believe that if the safety device is utilized, it will properly perform its function.
Last, but not least, the spring-loaded cables of the safety device have a tendency wrap around the worker's body during use. Not only is this aggravating for the workers, but the presence of the cable can interfere with their ability to properly perform their tasks. Experience has shown this problem to be particularly acute in hot weather, when the workers are wearing less clothing and the metal cables of the safety device chafe the workers. Not surprisingly, this failing, perhaps even more than the others, leads the workers to avoid using the device and to continue the dangerous practice of working on rooftops without safety devices of any kind.
Accordingly, there is a need in the art for a roofing safety device which can be used on a wide variety of roof configurations, which will be both quick and easy to install, and be comfortable for the worker.